This study investigated how changes in the material properties of a landing mat could minimise ground reaction forces (GRF) and internal loading on a gymnast during landing. A multi-layer model of a gymnastics competition landing mat and a subject-specific seven link wobbling mass model of a gymnast were developed to address this aim. Landing mat properties (stiffness and damping) were optimise...

We introduce a model that describes spherical oscillations of encapsulated microbubbles in an unbounded surrounding fluid. A Rayleigh–Plesset-like equation is derived by coupling the Navier–Stokes fluid dynamics with Navier solid via internal/external boundary conditions. While previous models were restricted to incompressible isotropic shells, shell modeled here as compressible viscoelastic ma...

This study investigated how changes in the material properties of a landing mat could minimise ground reaction forces (GRF) and internal loading on a gymnast during landing. A multi-layer model of a gymnastics competition landing mat and a subject-specific seven link wobbling mass model of a gymnast were developed to address this aim. Landing mat properties (stiffness and damping) were optimise...

During switching of disconnectors (DS) in GIS a varying number of pre-strikes and re-strikes occur. Due to the very short duration of the voltage collapse, traveling surges are generated in the busbar duct. These very fast transient overvoltages (VFTO) can become the limiting dielectric stress which defines the dimensions at UHV voltage levels. The decision shall be based on the maximum VFTO pe...

Piezoelectric-based shunt dampers are developed in recent years because of simplicity in comparison with other methods. In these methods, a part of converted mechanical energy is stored in the internal el...

To facilitate the damping matching of dampers for vehicle passive suspensions, this paper proposes an analytical matching method of the optimal piecewise linear damping characteristics curve. Based on the vehicle vibration model, taking the suspension dynamic deflection as the constraint, by the vibration acceleration and the wheel dynamic load, an objective function about the relative damping ...

A generalised method for the identification of the parameters which describe the dynamic properties of media between coupled substructures using measured FRFs is presented in this paper. The effort is mainly focused on the development of this generalised method and the improvement of its constituent algorithms. The method presented here is more general and more practical in some aspects when co...

In this paper, following a two-stage methodology, the differential quadrature element (DQE) model of a three-story frame structure is updated for the vibration analysis. In the first stage, the mass and stiffness matrices are updated using the experimental natural frequencies. Then, having the updated mass and stiffness matrices, the structural damping matrix is updated to minimize the error be...

For conservative mechanical systems, the so-called Caughey series are known to define the class of damping matrices that preserve eigenspaces. In particular, for finite-dimensional systems, these matrices prove to be a polynomial of one reduced matrix, which depends on the mass and stiffness matrices. Damping is ensured whatever the eigenvalues of the conservative problem if and only if the pol...

the interline power flow controller (ipfc) is a concept of the facts controller for series compensation which can inject a voltage with controllable magnitude and phase angle among multi lines. this paper proposes a novel ipfc-based damping neuro-control scheme using pso for damping oscil la t i o ns in a power system to improve power system stability. the add i tion of a supplementary controll...